diff --git a/example/src/main/java/it/tdlight/example/Example.java b/example/src/main/java/it/tdlight/example/Example.java
index 141a403..b6a234f 100644
--- a/example/src/main/java/it/tdlight/example/Example.java
+++ b/example/src/main/java/it/tdlight/example/Example.java
@@ -56,7 +56,7 @@ public final class Example {
 			SimpleTelegramClientBuilder clientBuilder = clientFactory.builder(settings);
 
 			// Configure the authentication info
-			SimpleAuthenticationSupplier<?> authenticationData = AuthenticationSupplier.testUser(3210); // Replace with AuthenticationSupplier.consoleLogin(), or .user(xxx), or .bot(xxx);
+			SimpleAuthenticationSupplier<?> authenticationData = AuthenticationSupplier.testUser(7381); // Replace with AuthenticationSupplier.consoleLogin(), or .user(xxx), or .bot(xxx);
 
 			// Add an example update handler that prints when the bot is started
 			clientBuilder.addUpdateHandler(TdApi.UpdateAuthorizationState.class, Example::onUpdateAuthorizationState);
diff --git a/tdlight-java/src/main/java/it/tdlight/client/AuthenticationSupplier.java b/tdlight-java/src/main/java/it/tdlight/client/AuthenticationSupplier.java
index 5483874..f9d129f 100644
--- a/tdlight-java/src/main/java/it/tdlight/client/AuthenticationSupplier.java
+++ b/tdlight-java/src/main/java/it/tdlight/client/AuthenticationSupplier.java
@@ -15,7 +15,7 @@ public interface AuthenticationSupplier<T extends AuthenticationData> {
 		if (value > 9999) {
 			throw new IllegalArgumentException("value must be lower than 10000");
 		}
-		return new AuthenticationDataImpl("999664" + value, null, true);
+		return new AuthenticationDataImpl("999662" + value, null, true);
 	}
 
 	CompletableFuture<T> get();
diff --git a/tdlight-java/src/main/java/it/tdlight/client/SimpleTelegramClient.java b/tdlight-java/src/main/java/it/tdlight/client/SimpleTelegramClient.java
index 0b8dc2b..0575100 100644
--- a/tdlight-java/src/main/java/it/tdlight/client/SimpleTelegramClient.java
+++ b/tdlight-java/src/main/java/it/tdlight/client/SimpleTelegramClient.java
@@ -125,8 +125,13 @@ public final class SimpleTelegramClient implements Authenticable, MutableTelegra
 			if (!((AuthenticationDataImpl) authenticationData).isBot()
 					&& ((AuthenticationDataImpl) authenticationData).isTest()) {
 				String phoneNumber = ((AuthenticationDataImpl) authenticationData).getUserPhoneNumber();
-				String substring = phoneNumber.substring(5, 6);
-				return substring + substring + substring + substring;
+				String loginCodeChar = phoneNumber.substring(5, 6);
+				StringBuilder sb = new StringBuilder();
+				//noinspection StringRepeatCanBeUsed
+				for (int i = 0; i < 5; i++) {
+					sb.append(loginCodeChar);
+				}
+				return sb.toString();
 			}
 		}
 		return null;